23. Sealab 2021 (2000-2005, Adult Swim)
Sealab 2021 debuted along with a whole host of other animated comedies on Cartoon Network back in 2000, but it easily stood out as one of the best. Featuring recycled animation from the mostly forgotten Hanna-Barbera cartoon Sealab 2020, the show re-dubbed that one's voices and turned it into one of the network's most offbeat cartoons.
Set a year after Sealab 2020, 2021 portrayed the Sealab's crew as sexually charged slackers with little ambition or intelligence. Its brand of surreal humor went on to set the tone for the rest of the shows on Adult Swim, but it never reached the heights of tits peers during the same time block.